The present invention relates to a distributed computer system including a plurality of computers linked with each other via a network such as a local area network (LAN) and, in particular, to a technology of achieving an automatic operation thereof.
There have been broadly utilized distributed computer systems including a plurality of computers coupled with each other via a network, for example, an LAN for conducting operations in a distributed processing fashion. In regard to the distributed computer system of this kind, there has been known an automatic operation technology to carry out a control operation in which the computers of the system are automatically started and/or terminated to save human power in the system operation.
As a technology associated with the automatic operation of the distributed computer system, there has been known an automatic operation system described in the Hitachi's Manual "A Guide to Operation for Integrate Automatic Operation Monitor "AOMPLUS", Program for VOS 3", 1991, September. The automatic operation system relates to a composite processor system in which each processor thereof is started or terminated according to a schedule beforehand loaded therein. The schedule is set, for example, as described in page 30 of the Hitachi 's Manual. Namely, the user of the system creates at least one schedule pattern defining a starting and terminating schedule for each processor. In the daily operation, the user specifies the pattern or one of the schedule patterns for the pertinent day to thereby generate the daily schedule.
In short, defining the start/termination schedule for each computer, the user can apply the conventional automatic operation system to the distributed computer system.
In the distributed computer system, however, various functions are distributed to the respective computers to increase usability of the system. In general, each computer executes processing by use of resources of hardware and software of the other computers. Consequently, for one of the computers of the distributed computer system to accomplish a desired operation, there is required a relation of dependence, namely, it is necessary that the other computers are also in operation. When the system size of the distributed computer system is increased, the dependence becomes more complex.
In consequence, when the automatic operation system of the prior art is applied to the distributed computer system, the user is required to examine the dependence between the computers such that the start and termination schedule of each computer is decided in consideration of the dependence. In other words, it is necessary for the user to guarantee that the complicated dependence between the computer is appropriately reflected on the start and termination schedule. However, it is difficult for the user to recognize the complex dependence between the computers of the distributed computer system, which increases load imposed on the user in the creation of the start and termination schedule.